Thanks for this very helpful response – I’m in post-production so I have very little control over what gets handed to me, but I’m going to stress from now on that people wait at least ten seconds before pulling cards.
In this case however, the card was archiving a live feed, and according to the person overseeing it, the device stopped recording when it switched to that card. Then she started it again and it stopped – so something else happened here, who knows what. I know all the cards were formatted and tested before they started…
Fortunately I was misinformed about the other two cards; they only needed to be recovered and we have everything from those.
We’re going to be using Sandisk Extreme III cards exclusively from now on in any case.